He's a baby just testing boundaries. And since he IS a baby, you need to be careful how you react.

I'd just put a leash/tab on him and calmly remove him from the cat(s) and/or crate him for a bit. What's really going on is he's not 'coming' when you call him off the cats.

So what you REALLY need to do is work on his general obedience (come) with distractions (cats). Easiest way and he's the perfect age, is to go to puppy/dog classes. Perfect way to gain the calm leadership skills you need to TEACH him to listen and learn in any place with anything going on.